Sink



FIG. 1 is a top, front, right perspective view of a sink showing my new design;

FIG. 2 is a top, front, left perspective view thereof;

FIG. 3 is a front isometric view thereof;

FIG. 4 is a right side isometric view thereof;

FIG. 5 is a left side isometric view thereof; and,

FIG. 6 is a top isometric view thereof.

The broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The broken lines showing the remainder of the sink represent unclaimed subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a sink, as shown and described. 